A flywheel in a vehicle is mounted between an end of an engine crankshaft and an input shaft of a transmission, and acts to reduce torsional vibration caused by torque variations during the process of torque transmission between the engine and transmission. Also, a clutch system is provided between the flywheel and the transmission input shaft. The clutch system transfers or blocks the transfer of engine power. The clutch system also acts to reduce gear rattle generated from torque variations, booming, and vibration and noise generated during abrupt acceleration and deceleration of the vehicle.
To enable the above dampening operation and to allow for the smooth operation at high output and torque, it is necessary to increase the dampening characteristics of clutch disks. Accordingly, an increase in an operational angle and a reduction in a rigidity of springs are required.
However, in existing clutch systems, it is generally not possible to increase the operational angle of the springs and reduce the rigidity of the same as a result of structural and layout constraints. A dual mass flywheel has been used to remedy this problem. The dual mass flywheel includes a primary mass member and a secondary mass member, and a spring is mounted between these two elements. Thus a greater reduction in rigidity and increase in the operational angle may be realized compared to existing clutch disk dampers. Also, by using torsional dampening characteristics, the above functions of the clutch system may be maximized.
However, conventional dual mass flywheels typically include a chamber formed between the primary and secondary mass members with at least one spring disposed therein and surrounded by grease filling the chamber. Sealing such a conventional dual mass flywheel, with grease in the assembly is difficult, and as a result of the complicated structure, assembly and disassembly are troublesome, and production costs are significant. Further, it is not possible to effectively perform dampening based on the size of engine torque.
The information discussed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.